Social networks generate a large number of posts, also referred to herein as documents, every day, and sorting out the posts is important so as to present the most relevant content for each user. A key part of sorting posts includes determining what the post is about. Having a good title for the post is a great help in determining the subject of the content and how to sort and classify the post.
Some approaches for determining the title of a document rely on the document format or metadata fields. However, these methods do not work well for popular social media networks, such as Twitter®'s tweets and Facebook®'s posts, which do not have rich format or metadata information and often include noisy information unrelated to the real subject of the document.